AT&T has announced new data plans for smartphone and tablet customers that will affect both iPhone and iPad users. The new smartphone data plans include AT&T Data Plus 300MB, which includes 300MB of monthly data for $20, AT&T Data Pro 3GB, which offers 3GB for $30, and AT&T Data Pro 5GB, which offers 5GB for $50 and also includes mobile hotspot tethering. Customers on the latter two plans can pay $10 per additional gigabyte, while Data Plus customers get an extra 300MB for $20. For the iPad, AT&T DataConnect 3GB includes 3GB for $30, while AT&T DataConnect 5GB runs $50 and includes 5GB of data. All five new plans will launch this Sunday, January 22; existing customers will have the choice of keeping their current plans or choosing from one of the new options.